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"'CARD 31 PUFF ADDER
The puff adder is one of Africa~ most feared venomous snakes. When threatened, this thickset viper puffs itself up and hisses
loudly before it strikes and possibly kills its attacker.
KEY FACTS
SIZE
Length: 2-5 ft.
BREEDING
Sexual maturity: About 2 years.
Breeding season: October to
December.
No. of young: 20-30. May be
more than 50.
Incubation: About 5 months. Eggs
usually hatch inside the female.
LIFESTYLE
Habit: Solitary; mainly nocturnal.
Diet: Various small mammals,
birds, amphibians, and reptiles.
Lifespan: Maximum on record, 15
years in captivity.
RELATED SPECIES
There are 8 species in the genus
Bitis. The longest is the Gaboon
viper, Bitis gabonica, and the short
est is the dwarf viper, B. peringueyi.
Range of the puff adder.
DISTRIBUTION
The puff adder is found throughout most of the African conti
nent. It lives everywhere except at heights of over 6,500 feet,
in the rainforest interior, and in the most arid deserts. Its range
extends into the Arab peninsula.
CONSERVATION
Although it is hunted by other predators, and it is feared by
humans, the puff adder is not in any immediate danger.
FEATURES OF THE PUFF ADDER
Head: Broad, flattened, and spearshaped. Distinct from the rest of the body. Contains large jaw muscles and venom-producing glands.
Fangs: Sharp, . hollow tubes through which venom passes into the victim's body. When not in use, the fangs fold back inside the mouth.
,-
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Skin: Covered with rough scales that dull the snake's colors. The colors vary depending on habitat, but most snakes are marked with V-shaped bands. The female is more brightly colored than the male.
Body: Thickset. Its belly is flat, and its sides slope down in a triangular shape. Its tail is easily distinguished. The male is smaller than the female.
0160200611 PACKET 61
The puff adder's coloring varies to match
the sand or soil of its habitat. This camouflage helps
the snake to hide from predators and to ambush its prey
successfully. On the other hand, this excellent adaptation
makes the snake difficult for humans to notice. Many
people have been bitten and seriously poisoned after
treading on a well-camouflaged puff adder.
~ HABITS The puff adder is widely distrib
uted throughout most of Africa.
It lives in a variety of habitats,
from deserts to tropical forests.
It may stray onto farmland and
prey on chickens and on the rats
it finds in grain storage areas.
The puff adder is usually about
three feet long with a thick body
and broad head. As it moves for
ward, it keeps its body straight,
contracting muscles on its belly
to push its rough scales against
the ground. This is known as
rectilinear movement.
The puff adder is active mainly
at night when it feeds. During
the day it may climb into a shrub
to bask in the sun, especially if it
is pregnant. The snake may go
into water and at night often
lies on tarred roads that retain
heat from the sun.
The adder may be attacked by
birds of prey, mongooses, wart
hogs, and other snakes. When
disturbed, the snake inflates it
self and hisses. If necessary, it
raises the front of its body into
an S shape and lunges.
~ BREEDING The puff adder breeds between
October and December. The
male snake engages in "com
bat dances" with other males
to win the right to mate with a
particular female. When mat
ing, he curls his tail beneath
the female's and inserts his sex
organs into a cavity at the end
of her body called the cloaca. Fertilized eggs remain inside
the female until March or April.
The eggs are thin and often
tear as they are being laid, so
the young snakes have usually
hatched by the time they leave
the mother's body. Snakes that
Left: The puff adder transfers scent from its tongue to the Jacobson's organ, a scent organ in its mouth.
DID YOU KNOW? • The puff adder causes over half of the serious snake bites
inflicted on humans in Africa.
• The puff adder produces 100
to 350 milligrams of venom.
Just 100 milligrams is enough
to kill a human.
• The puff adder stores a great deal of body fat. Local doctors
collect the fat and use it as a
give birth to live young in this
way are called ovoviviparous. Usually 20 to 30 young are
born at once, although births
of over 80 snakes have been re
corded. The young are about
eight inches long and can im
mediately kill small animals
such as mice and rats. At first,
however, the young usually do
not hunt. Instead, they molt (shed their skin) and feed off
the yolk sac with which they
are born. During this time they
grow longer and wider. By the
age of two, the puff adder is
sexually mature.
Right: The puff adder is solitary. The male and female do not stay together after mating.
treatment for rheumatism.
• In 1964 the director of the Salt Lake City Zoo died from
a puff adder bite.
• There is a deep pit above the puff adder's nostrils, but its pur
pose remains a mystery.
• The Cape puff adder subspecies lives only in a small
mountain area in South Africa.
~ DEFENSES The puff adder's variable color
ation is a vital adaptation to its
environment. Desert-dwelling
adders are light yellowish brown
with dark brown, pale-edged
chevrons (V-shaped bands). In
tropical forests puff adders are
dark brown with brown and
olive patterns that offer camou
flage in the leaf debris.
~ FOOD & FEEDING The puff adder preys mainly on
small mammals, but it also at
tacks birds, amphibians, and
lizards. Camouflaged by its col
oring, the snake may remain
motionless for several hours,
waiting for prey to come with
in striking distance.
The puff adder does not need
to use its venom on small prey
such as frogs, which it can seize
in its jaws and swallow alive. It
Left: The puff adder's fangs fold back on elastic hinges to allow prey to be swallowed.
If it is discovered by a preda
tor, the adder hisses loudly and
backs away. If this defense fails,
the snake strikes. A potent ven
om is pumped from glands in
its head, through its fangs, into
the victim's body. The area near
the bite burns, swells, and blis
ters. Fatal heart or kidney failure
usually follows.
bites larger prey with its fangs
and injects them with deadly
venom. The venom takes time
to affect its victim, so the ani
mal may flee before dying. The
puff adder then follows the trail,
finds the corpse, and eats it.
When eating, the puff adder
seizes its prey with the teeth in
its lower jaw and swallows the
animal whole. It keeps its head
up, while muscular movements
carry the food down to its stom
ach. A long period of rest and
digestion follows.
'" CARD 32 SLOWWORM "~ ____________________ G __ RO_U_P __ 3:_R_E_P_TI_l_ES_& __ A_M_P_H_IB_I_A_N_S_~~
ORDER FAMILY GENUS &; SPECIES Squamata Anguidae Anguis fragi/is
The slowworm may look like a snake, but it is really a lizard without any legs. If it is alarmed, it may shed its tail
in order to distract an attacker.
'\l KEY FACTS
I~ I SIZES ~ Length: 11-12 in . at maturity,
but may continue growing to a
maximum of 20 in.
BREEDING
Sexual maturity: Male, 3 years.
Female, 4-5 years.
Mating season: Spring.
Gestation: From 4 months to
nearly a year, depending on
temperature.
No. of young: 6-12, occasionally
up to 20.
LIFESTYLE Range of the slowworm.
DISTRIBUTION Habit: Solitary in summer. Often
hibernates in groups.
Diet: Mainly slugs, snails, earth
worms; also insects and spiders.
The slowworm is found throughout mainland Europe,
southern Scandinavia, Great Britain, and southwest Asia.
CONSERVATION RELATED SPECIES
The many snakelike lizards in the
family Anguidae include the large
European glass lizard and the
California legless lizard.
Although it is occasionally killed by people who think it is a
venomous snake, the slowworm is still common wherever its
habitat has remained intact.
HOW TO TELL A SLOWWORM FROM A SNAKE
The slowworm is a limbless lizard, not a snake. Here are some ways that snakes differ from slowworms.
Tongue:$nakes have long forked tongues (above) . Siowworms have notched tongues.
Scales: Snakes have rough scales (right). Slowworms have smooth scales.
Eyes: Snakes have lidless eyes __ that cannot be closed (right). Siowworms have eyelids and are able to blink.
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When in danger, the slowworm can rupture special bones and shed its tail. Muscles and blood vessels also part to make a clean break.
The new tail is made of cartilage. It is shorter and contains no special bones, so the shedding action cannot be repeated.
0160200461 PACKET 46
The slowworm is one of several legless burrowing
lizards that are found in different parts of the world.
This elongated creature both looks and moves like
a snake, wriggling its highly polished muscular body
through soil and vegetation. Although it cannot
be said to move quickly, the slowworm is not
as lethargic as its name suggests.
The slowworm relies on the sun's heat to raise its body temperature until its muscles and internal organs work efficiently. It hibernates in winter, when the sun is weak and there is little food. Up to 30 slowworms may hibernate together in a burrow or under a rock, lying dormant until spring's warmth penetrates their retreat.
DID YOU KNOW? • One captive slowworm lived for 54 years. • A mature male slowworm may have so many bright blue spots that it looks blue all over. • The slowworm's skin is embedded with bony plates, forming an outer shell that reinforces the bones within.
~ FOOD & HUNTING The slowworm prefers to hunt easy prey such as slugs, snails, and earthworms, but it occasionally takes insects and spiders. It is often welcomed by gardeners because it eats the small white slugs that cause damage to vegetables.
The slowworm is most active at twilight or after a rainfall,
Left: The slowworm's skin is not slimy. The scales are dry and as smooth as polished metal.
Right: The slowworm usually seizes prey by the middle of the body. Here it bears down on a nettled slug.
~BREEDING The slowworm mates soon after it emerges from hibernation in April or May. The males compete for mates, seizing each other by the head or neck, entwining their bodies, and writhing over the ground. The act of mating looks similar but is less violent and damaging.
The pregnant female spends many hours in the summer sun, raising her body temperature to between 70 and 7l F to speed the development of her young. If the summer is warm, the young may be born in late August, but cool weather will
when slugs and earthworms are most numerous. Gliding up on its polished scales, it seizes its victim in its small mouth and slowly eats it. Unlike a snake, it cannot stretch its mouth around large prey, so anything larger than a small slug must be chewed thoroughly before it is swallowed.
delay the birth until October or even the next spring.
The slowworm is ovoviviparous -the female produces eggs without shells that hatch inside her body. The six to twelve young are very active and can feed themselves almost immediately at birth, but they take several years to grow to their full size. The young are yellow on top and black on the bottom, with a dark stripe down the back. Upon reaching adulthood they turn brown or sandy gray. The female's flanks and underside are darker.
~ DEFENSES Frogs and toads prey on young slowworms, and adults may be attacked by snakes, hedgehogs, foxes, and birds of prey.
If threatened, a slowworm tries to escape. But if necessary, it resorts to an extraordinary defense tactic-it snaps in two.
The tail bones nearest the body have weak areas that let
the bones snap cleanly and easily. If alarmed, the slowworm ruptures the bones, and a portion of the tail is thrown off. For a few minutes the severed tail writhes convulsively, distracting the predator while its former owner escapes.
The stump heals quickly, and a new, shorter tail grows. The tail bones are not replaced and the new tail is made of cartilage, so the slowworm cannot shed its tail again.
[g NATUREWATCH I The slowworm basks in full sun in spring but takes shelter from direct heat later in the year. It can often be found in compost heaps or piles of twigs. To the touch, the slowworm is dry with a glassy feel. If alarmed, it may shed its tail, reducing its future chances of survival.
~~3U
NORTH AMERICAN =~:=~AMPHIBIANS ~ '(~---------------- ~~~ ... CLASS ... ORDER FAMILY '" GENUS
'11IIIIIIII Amphibia '11IIIIIIII Salientia Hylidae '11IIIIIIII Hyla
North American treefrogs are a varied and colorful assortment of amphibians. They are known for their loud calls and can be
easily recognized by their enlarged, adhesive toe pads.
'S:J---'S..EY FACTS
I~ I SIZE ~ Length: ~-5 ~ in ., depending on the
species .
BREEDING
Sexual maturity: 1 year.
Mating season: Varies in different
parts of the country.
No. of eggs: Several hundred to
2,000, depending on the species.
Hatching time: 2-10 days, depend
ing on the species.
Metamorphosis: 1-2 months.
LIFESTYLE
Habit: Solitary except in the mating
season, when large numbers congre
gate in ponds and marshes.
Diet: Small insects and spiders.
RELATED SPECIES
There are 600 members of the family
Hylidae in the world and 14 species
of Hyla in North America. Cricket
frogs (genus Acris) and chorus frogs
(Pseudacris) are other North Ameri
can members of this family.
Range of North American treefrogs.
DISTRIBUTION
Found from southwestern Canada and the Maritime Provinces
south to western Mexico and the Gulf Coast but absent from
the Great Plains.
CONSERVATION
Most North American treefrogs are still common in their ranges,
but they suffer from pesticides and habitat destruction, especial
ly of wetlands. The pine barrens treefrog is a threatened species.
FEATURES OF NORTH AMERICAN TREEFROGS
Spring peeper, Hyla crucifer: Distinguished by its small size , tan colori ng, and the dark X-shape ...A .... on its back. Throat pouch: This
organ is inflated by the male to produce a sound that attracts a female .
Green treefrog, Hyla cinerea: Colored bright green, usually with a white stripe running down its side.
Gray treefrog, Hyla versicolor: Easily identified by its mottled coloring with dark blotches on a predominantly greenish or grayish background.
~~~~JIo};2:" '~'~!i;;~~~~~~~ Toe pads: The swollen tips ~ of its toes enable a treefrog
to cling to vertical su rfaces.
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North American treefrogs use their adhesive toe pads
to climb through foliage in search of insects. For most of
the year these small, well-camouflaged amphibians are
hidden in the woods and are rarely seen. But during the
mating season, large numbers gather near water.
~ HABITS There are treefrogs on almost every continent. The 14 species in North America range in size from the Cuban treefrog, which is more than five inches long, to the half-inch little grass frog .
The calls of some treefrogs, such as that of the well-named spring peeper in the East, are recognized as one of the first signs of spring . The Pacific treefrog, which is abundant in the hills around Hollywood, has become known for its loud, twopart musical call . Its voice can
be heard on the soundtracks of many movies.
Outside the breeding season, most treefrogs are nocturnal, forest-dwelling hunters of small insects. To protect themselves from drying out in hot summer weather, some treefrogs coat themselves with a layer of mucus that seals in the moisture in their bodies. In winter, many species hibernate.
Above: The Pacific treefrog may be green, tan, or black. It is the most common treefrog on the West Coast.
I' >i1t.J NATUREWATCH North American treefrogs, such as the tiny spring peeper, are most often seen during the mating season, when males and females emerge from the woods to mate and lay eggs in ponds and marshes. At other times of year, these frogs are secretive woodland creatures. But the males' distinctive calls may sometimes be heard in warm months outside the mating season-especially during a shower or immediately after one.
~ BREEDING North American treefrogs spend most of the warm months hunt~ ing insects in woodlands. However, once a year, usually in the spring, huge numbers gather in weedy ponds and marshes to mate and lay eggs.
The male of each species has a distinctive call, enabling the females of that species to recognize him. When a female appears, the male grasps her just behind her front legs and fertilizes the clusters of eggs as
she lays them. Most species lay several hundred eggs, but a few lay up to 2,000.
The eggs hatch in two to ten days, depending on the species and on the temperature of the water. A tiny tadpole emerges from each egg. In one to two months, the tadpole metamorphoses, changing into a small version of the adult. The young frog hops into the woodlands nearby and does not reappear until the next breeding season.
DID YOU KNOW? • The spring peeper's species name is crucifer, which means "cross-bearer." It refers to the cross on this tiny frog's back. • It has recently been discovered that the gray treefrog is not a single species, but rather two outwardly identical species that differ genetically. The rate at which they call is also different. Scientists have not yet determined the ranges of these two frogs . • The pine barrens treefrog is the rarest treefrog in North America. It lives in only a few
~ FOOD &: FEEDING North American treefrogs feed on a variety of insects such as flies, leafhoppers, and beetles. As their name implies, treefrogs hunt mostly in trees or bushes,
Left: The spring peeper is named for the high-pitched peeping sound it produces in the spring.
Left: The male gray treefrog is often heard uttering its loud, shrill trill from the trees. But, because of its mottled coloring, the frog itself is usually difficult to see. The skin of the gray treefrog is wartier than that of most other treefrogs.
sandy areas with pines from New Jersey to the Carolinas. • The bird-voiced treefrog is a common southern species, with toxic skin secretions that can cause watery eyes and nasal congestion in people who handle it. • Most treefrogs are solitary nocturnal hunters. But the squirrel treefrog, which lives in the Southeast, frequently spends the day in a tightly packed cluster. The group's members conserve moisture by huddling together.
employing their sticky toe pads to cling to the leaves.
Like all other frogs, a treefrog catches its insect prey by quickly shooting out its tongue. The instant an insect sticks to the tongue, the treefrog pulls the tongue back in .
BUSHMASTER
CLASS Reptilia
ORDER Squamata
GROUP 3: REPTILES &: AMPHIBIANS FAMILY Crotalidae
~ GENUS &: SPECIES ~ Lachesis muta
The bushmaster is the largest venomous snake in the Americas. But despite its great size, it is rarely seen in the dense
vegetation of its rainforest habitat.
KEY FACTS
SIZES
Length: Average, 8-10 ft. Maxi
mum, 12 ft. Weight: 6-11 lb.
BREEDING
Sexual maturity: 2 years.
Breeding season: Probably spring.
Eggs: About 10; white.
Hatching time: 9 weeks.
LIFESTYLE
Habit: Solitary. Conceals itself by
day; hunts by night.
Diet: Mainly small mammals.
Lifespan: 20 years or more.
RELATED SPECIES
The family Crotalidae includes
rattlesnakes, moccasins, and sev
eral species of fer-de-lance. Most
crotalids are found in the Americas,
but some inhabit the Old World.
Range of the bushmaster.
DISTRIBUTION
Found in tropical rainforests in Central America and northern
parts of South America from Costa Rica to Brazil. Also occurs on
the island of Trinidad.
CONSERVATION
Because of the bushmaster's habitat and lifestyle, precise popu
lation figures are not known. But it can be assumed that it is
suffering from the destruction of the rainforests.
FEATURES OF THE BUSHMASTER CARING FOR THE EGGS
Body: Slender, long (up to 10 feet), and almost triangular in cross section . The skin is covered in rough scales with knobby protrusions.
Coloring: Pale or pinkish tan with distinctive dark brown diamondshaped pattern along the back. This provides camouflage among the dead leaves of the forest floor.
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Head: Large and wedge-shaped, tapering toward the front. Cov
ered with small , irregularly shaped scales.
Eyes: Large vertical pupils
give good nighttime vision.
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Laying: The female lays about 10 large white eggs in a hollow in the ground . The eggs are larger than a hen's eggs.
Incubating: Unlike most other snakes, the female bushmaster guards the eggs by coiling her body around them until they are ready to hatch.
0160200571 PACKET 57
The bushmaster is one of a group of snakes
known as pit vipers. Like all of these snakes, the
bushmaster is equipped with special organs that detect
another animal's body heat, alerting the snake to passing
prey in the nighttime darkness of the forest. Once it has
located its victim, the bushmaster bends the front part of its
body into an 5 shape to make a lightning strike.
~ HABITS The bushmaster lives in tropical rainforests or in forests on the lower slopes of mountains, where there is a minimum rainfall of 79 to 158 inches a year. The humid, dense jungles of South America provide the bushmaster with an ideal habitat, since it needs a warm, moist climate and prefers to avoid direct sunlight.
The shy bushmaster avoids contact with humans. During the day it hides in dense undergrowth, where it is well camouflaged against the dead leaves on the forest floor. It
emerges from cover only at night to search for prey.
Like most venomous creatures, the bushmaster uses its toxin only to kill prey. It defends itself by biting only in extreme cases, preferring to scare away its enemies rather than waste its precious venom. To deter predators, the bushmaster thrashes its tail against vegetation. The hard, hollow tail tip produces a warning sound like that of a rattlesnake.
Right: The markings on the bushmaster's skin enable it to blend in with dead foliage.
~ BREEDI NG The normally solitary bushmaster relies on a powerful scent to track down a mate. The male snake approaches the female, stroking her chin with his head. If she responds, the two snakes entwine their bodies in an elaborate courtship ritual before finally mating.
The female lays about 1 0 large white eggs in a shallow hole in the ground and covers them with damp earth to keep them
Left: The bushmaster is the largest venomous snake in the Western Hemispheres.
• Deprived of its senses of sight and smell in an experiment, a bushmaster was still able to strike its prey. • There are only 25 recorded cases of bushmasters biting humans. Five of these bites were fatal. • According to a South American legend, the bushmaster
at the right temperature. She coils her body around the eggs to protect them until they hatch.
After about nine weeks the young snakes break out of the eggs, using a special egg tooth that grows on the upper jaw and drops off shortly after hatching. The fully developed young can fend for themselves as soon as they hatch. But they do not reach sexual maturity until they are at least two years old.
Right: The bushmaster is the only pit viper that lays eggs. Other pit vipers bear live young.
can put out fires. Different legends tell of fully grown snakes that suckled from cows and sleeping women. • The bushmaster is called "pineapple snake" because of its rough, knobby skin. • Captive bushmasters do not adapt well because they refuse to eat.
~ FOOD &: HUNTING The bushmaster feeds mainly on rodents of various sizes. It hunts at night, lying motionless in the undergrowth waiting for an unsuspecting animal to pass by.
Like all pit vipers, the bushmaster has two pit organs located between the nostrils and the eyes. It is thought that these organs act as sensory devices, responding to the heat given off by other animals. The bushmaster uses its pit organs to detect prey. Once it has located its victim, the snake can strike. It sinks its long, tubular fangs into
Left: The bushmaster has two special pit organs that can sense the body heat of other animals. With these organs and its sensitive eyes, the bushmaster can detect prey from a distance of 20 inches.
the animal's body and injects a large quantity of venom into its bloodstream. This venom attacks the blood vessels, causing a massive heart attack.
With its specially hinged jaws, the bushmaster can open its mouth wide enough to swallow prey whole. The muscles of the esophagus (throat) slowly move the dead animal into the bushmaster's body, and powerful juices in the stomach immediately begin to digest the prey. The bones and hair are either digested or passed out in the feces later.
"" CARD 35 SPECTACLED CAIMAN ,, _______________________ G_R_O_U_P_3_:_R_EP_T_ll_E_S_& __ A_M_P_H_IB_IA __ N_S _~~ ... ORDER FAMILY GENUS & SPECIES
"IIIIIIII Crocodilia Alligatoridae Caiman crocodilus
A relative of the alligator, the spectacled caiman is found throughout Central and South America. Its name refers to the
bony ridges above its eyes and snout that look like a pair of glasses.
KEY FACTS
SIZES
Length: Up to 8 ft. Weight: Up to about 65 lb .
BREEDING
Sexual maturity: Usually by 8
years of age. Females have been
known to breed at 4 years.
Breeding season: Beginning of
rainy season; usually April to June,
but varies with location.
No. of eggs: 25-30.
Incubation period: 4-8 weeks.
LIFESTYLE
Habit: Generally solitary; aquatic.
Diet: Mainly fish, crustaceans, and
mollusks.
Lifespan: Possibly to 60 years.
RELATED SPECIES
There are 4 other caimans: the
black caiman, broad-snouted
caiman, smooth-fronted caiman,
and dwarf caiman. All of them live
in the American tropics.
Range of the spectacled caiman.
DISTRIBUTION
Native to Central and South America, from Mexico in the
north to Paraguay in the south. Also found on some southern
Caribbean islands, including Trinidad.
CONSERVATION
The spectacled caiman's ability to survive in a wide variety of
habitats has enabled it to remain fairly numerous, despite its
being widely hunted.
THE SPECTACLED CAIMAN'S NEST Nest building and maintenance: After mating, the female spectacled caiman builds a nest close to the water's edge. First she scrapes up a pile of vegetation that may measu re 11f feet high by 3 feet wide. Then she crawls on top of the pile and presses it down with the weight of her body in order to shape the nest. Next she digs a hole in which she lays her eggs. Finally she covers the eggs with vegetation to help them incubate.
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nearby to keep away intruders.
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Broad-snouted caiman: Grows up to 8 feet long and has a distinctive wide snout.
Dwarf caiman: One of the smallest caimans, reaching only 5
, feet in length .
01 60200491 PACKET 49
The spectacled caiman lives in a vast region
that stretches from Mexico in the north to Paraguay
in the south. Throughout this range four subspecies,
or races, occupy separate geographical areas.
They are the common spectacled caiman, the
brown caiman, the Apaporis River caiman
and the Paraguay caiman or jacare.
~ HABITAT The four subspecies of spectacled caiman differ slightly in appearance and habit. The common spectacled caiman has been studied most widely. It is found in Venezuela, Colombia, Ecuador, Guiana, and the Amazon regions of Brazil, and on Trinidad and a few other Caribbean islands.
The common spectacled caiman lives in fresh water and prefers ponds and lakes to rivers. All races frequent marshes and swamps except the Apaporis River caiman, which lives only in the upper reaches of its namesake river in Colombia.
DID YOU KNOW? • The spectacled caiman was originally named Lacerta crocodilus by the great taxonomist Linnaeus. So it became known as Caiman crocodilus when the genus Caiman was accepted. But since caimans are more closely related to alligators, some experts feel this name
~ FOOD & HUNTING The spectacled caiman preys on a wide variety of fish and invertebrates, including water snails and crabs. Because it is a cold-blooded reptile, the spectacled caiman does not need to consume as much food as a warm-blooded animal of equal size. As a result, it can afford to be an opportunistic hunter, snapping up whatever prey comes within reach of its jaws. Such prey may include mammals and carrion (dead animals).
Right: The spectacled caiman will snap up anything in its path.
is misleading. They prefer to use the second-oldest name, Caiman sclerops.
• The baby "alligators" that are often sold to tourists in North America are, more often than not, young spectacled caimans that have been imported from Colombia.
Top left: The cold-blooded spectacled caiman likes to bask in the sun.
Left: A young spectacled caiman. Some youngsters stay close to their parents for 18 months before going offon their own.
Right: The spectacled caiman becomes sexually matureata certain size, not age.
~ SPECTACLED CAIMAN & MAN Large anaconda snakes and jaguars occasionally prey on spectacled caimans. But humans are the caiman's main enemy. Many of these reptiles are shot by cattle ranchers who mistakenly think they are a threat to livestock. But the majority fall victim to hunters who capture them for the pet
~ BREEDING The spectacled caiman is usually mature by its eighth year. In breeding season, the generally solitary adults seek each other out and then mate in shallow water.
The spectacled caiman usually hides its nest beneath a bush or shady cypress so the eggs will
trade and for sale to tourists. Because alligators are legally protected, the spectacled caiman is now the most popular and widely kept crocodilian. The large-eyed young are appealing, but they do not make good pets. Their specialized needs make them unsuitable for homes.
be protected from the sun. The female digs a cavity in the nest, where she deposits up to 30 eggs. The white eggs are about two to three inches long and up to one and a half inches wide. Once the clutch is complete, the female covers it with vegetation. The tropical heat and decaying plant matter provide warmth for incubation.
When the young reptiles hatch, they are 6 to 1 0 inches long, and their yellowish bodies are marked with black bands. It is not long before they must fend for themselves, and many fall victim to predators.
'" CARD 36
MARSUPIAL FROG "~ _____________________ G_R_O_U_P __ 3:_R_E_PT_I_lE_S_& __ A_M_P_H_IB_I_A_N_S _"~
.. CLASS ~ Amphibia
.. ORDER ~ Anura
.. FAMILY ~ Hylidae
.. GENUS ~ Gastrotheca
Marsupial frogs are named for marsupial mammals such as the kangaroo. Like these mammals, they carry their young in a pouch
to protect them until they are able to survive on their own.
KEY FACTS
SIZE
Length: 1-4 in .
BREEDING
Mating: Throughout the rainy sea
son. Females come to calling males
when they are ready to release
their eggs.
No. of eggs: 4-200, increasing
with size of species.
Development: Tadpoles usually re
leased after 3-4 months.
LIFESTYLE
Habit: Generally solitary; active at
night. Range of marsupial frogs.
DISTRIBUTION Diet: Tadpoles eat algae from rocks
and plants. Adults eat insects and
similar small animals.
RELATED SPECIES
Found in Central and South America, from lowland rainforests
to plateaus in the Andes over 13,000 feet above sea level.
CONSERVATION There are 39 Gastrotheca species
and 21 very similar species in 6
other genera. All belong to the
true tree frog family, Hylidae, which has 637 species through
out the world.
Several species of tropical frogs have disappeared in recent
years for no obvious reason . Marsupial frogs remain fairly com
mon, but many may be threatened by the destruction of their
rainforest habitat.
FEATURES OF MARSUPIAL FROGS
Dorsal pouch: Present only on females. Outside the breeding season, the pouch looks like a small slit on the frog's back. As fertilized eggs develop inside the pouch, it stretches to accommodate them. This makes the frog look swollen.
Birth of young: When the young are developed enough, the female opens her pouch and releases them. If she is "giving birth" to tadpoles, she positions herself carefully so that they fall into a pool of water.
Coloration: Varies greatly among species. Most have green or-brown
markings that'provide camouflage In their
tropical forest habitat.
© MCMXCII IMP BV/IMP INC WILDLIFE FACT FILETM PRINTED IN U.S.A.
loses water. The , frogs must stay
in damp, shady places where the
skin will not dry out.
Have long toes with suc
, tion disks that help the frogs
grip leaves and branches.
0160200601 PACKET 60
Female marsupial frogs are model parents.
They produce relatively few eggs and keep them in
a pouch. After the eggs hatch/ the young may develop
further inside the pouch/ which increases their chances
of survival. Most other frogs/ by contrast/ produce huge
numbers of eggs to compensate for the fact that most
will die or be eaten before reaching maturity.
~ HABITS Marsupial frogs live in the tropical forests of South and Central America. They spend their
lives in the trees foraging for food and rarely descend to the
ground. Their long toes have suction disks that give them a
powerful grip, so they can leap and climb with ease.
Marsupial frogs are active
mostly at night. As amphibians, they risk deadly dehydration if they are exposed to the sun. Because amphibian skin is usually not waterproof like the skin of
reptiles and mammals, frogs are able to soak up water when they need it. But their skin also lets
water in their bodies evaporate.
Marsupial frogs, like most tree
dwelling frogs, do not have easy access to pools of water in which to replenish moisture. As a re
sult, they must conserve what water they have.
By day most marsupial frogs lie in a damp, dark spot. They are concealed from enemies by
the shade and by their green and brown coloring. In several species this camouflage is enhanced by fleshy "horns" that
break up the frog's outline and make it less likely to be recognized for what it is.
Right: After releasing the young from her pouch, a female leaves them to fend for themselves.
~ FOOD &: FEEDING Marsupial frogs feed mainly on insects. Some species are agile hunters, leaping up and snatching flies from the air. But most species hunt insects that rest
on leaves or twigs. As long as an insect stays still,
it is safe. But the tiniest movement catches the frog's attention. For a few moments the
frog studies its prey and moves closer. If the insect does not
Left: With her pouch full of developing young, this female marsupial frog appears swollen.
DID YOU KNOW? • Marsupial frogs have a patch of very thin skin on their bellies. They use this skin like a
sponge to soak up moisture from damp leaves.
• Gastrotheca, marsupial frogs' genus name, means "stomach pouch." The frogs were given this name when they were first
discovered, and the purpose
move again, the frog may lose interest. But if the insect moves
again even just a little, the frog opens its mouth and its victim
is gone, snatched in a flick of the frog's long tongue.
To swallow its meal, the frog performs an unusual maneuver-it forces food down its
throat by retracting its eyeballs down to the roof of its mouth to create needed pressure.
Right: In some species the young marsupial frogs do not emerge until they are fully developed.
of the pouch was not clear.
• Some tree frog species have a different way of protecting their offspring. The poisonarrow frog carries its tadpoles
to a specially built nursery pool to develop in safety.
• In some marsupial frog species, the female's pouch holds
200 eggs.
~ BREEDING Rather than laying large num
bers of eggs and abandoning them, marsupial frogs care for their young until they have
developed enough to survive. The female has a pouch on her back that serves as an incuba
tor and nursery. The pouch has an opening near the female's
egg duct. As she lays her eggs, they are fertilized by a male that is clinging to her back. He then stuffs the eggs into the pouch with his hind feet.
The eggs develop and hatch inside the pouch. In some spe
cies, the young develop in the pouch into tiny, fully formed frogs. Since the young are not
Left: A male marsupial frog has a big vocal sac, and he calls every night until he attracts a mate. After mating, he leaves the female, who cares for the young alone.
released as tadpoles, the par
ents do not need to go near water in order to reproduce.
In other species, the young are ejected from the female's
pouch after a period of three to four months, while they are still tadpoles. The female finds a pool for them, either on the
ground or in a bromeliad-a plant that grows high in the trees and traps moisture in
its vaselike foliage. Using the long toes of her hind feet, she opens the pouch and scoops the tadpoles into the water.
There they change into tiny frogs and climb out to begin life in the trees.
"'CARD 37 GAVIAL "~ _____________________ G __ RO_U_P __ 3:_R_E_PT_I_l _ES_& __ A_M_P_H_IB_1_A_N_S_~~ ... CLASS
'11IIIIIIII Reptilia ORDER Crocody/ia
... FAMILY '11IIIIIIII Cavia/idae
GENUS &: SPECIES Cavia/is gangeticus
The gavial of India is one of the largest and strangest crocodiles. With its slender, sharp-toothed jaws, it is well equipped
to feed almost exclusively on fish.
KEY FACTS
SIZES
Length: Male, up to 21 ft., possi
bly longer. Female, up to 13ft .
Weight: Up to 2,200 lb.
BREEDING
Sexual maturity: 10 years.
Breeding season: From late winter
to spring.
No. of eggs: Average, 40; but up
to 97 recorded in 1 clutch.
Incubation: 2-3 months.
LIFESTYLE
Habit: Usually solitary or lives in
small groups.
Diet: Mainly fish; also some water
birds, crabs, and small mammals.
Range of the gavial .
DISTRIBUTION
RELATED SPECIES
The gavial is classified in a family
of its own. But the false gavial,
Tomistoma sch/ege/i, is grouped
among the true crocodiles in the
family Crocodi/idae.
Found in the Indus River system in Pakistan and western
India. A larger eastern population occurs in the rivers Ma
hanadi, Ganges, Brahmaputra, Kaladan, and Irawaddy.
CONSERVATION
The gavial is recovering from a serious decline, thanks to a
concerted conservation and captive breeding program. But
it is still listed as endangered.
FEATURES OF THE GAVIAL HOW THE GAVIAL FEEDS
Hide: Very tough and protective. Highly prized by hunters for the skin trade, although the gavial now receives some legal protection.
suit the gavial's aquatic life. Female uses them to dig a nest and to manipulate her eggs.
Movement: Unlike most crocodiles, the gavial cannot raise its massive body and tail off the ground to walk. Instead, it drags itself slowly forward .
Snout tip: A protruding lump of tissue develops on the mature male. Its precise function is unknown. It may be used to amplify the calls uttered by the male in the breeding season.
Snout: Very narrow for a crocodilian. More than 100
teeth intermesh when the jaws are cl.osed. The gavial has no lips to keep
out water. But like all crocodiles it can breathe through its nostrils while its mouth is full of water.
© MCMXCII IMP BV/IMP INC WILDLIFE FACT FILETM PRINTED IN U.S.A.
The snout is ideal for a swift underwater attack. Presenting little resistance to the water, it can be flicked to one side to slice into fish or snap shut to trap them.
0160200651 PACKET 65
The gavial has long been hunted for its smooth, durable
hide, which can be polished to a lustrous finish. Because
the remaining population has lost much of its freshwater
habitat to intensive rural development, sanctuaries have
been established in an attempt to save this endangered
species. But even though there are widespread captive
breeding programs, the gavial faces an uncertain future.
~ HABITS The gavial basks on sandbanks
but rarely goes far from water. It
prefers clear, fast-moving rivers
with an occasional deep pool
where it can lie half-submerged,
with only its eyes and nostrils
above the surface.
Reptiles depend on external
warmth to maintain their body
temperature. Water is often the
warmest place to be because
Right: With more than a hundred teeth in its slender jaws, the gavial is well equipped to trap fish.
water temperature is more sta
ble than air temperature. Since
the gavial lives farther north
than most crocodilians, it often
spends winter nights in the wa
ter. It sinks to the bottom, where
the water is warmest. Its body
processes slow down, so it needs
little oxygen. If it has to breathe,
it surfaces for air but soon re
turns to the warm depths.
~ FOOD &: HUNTING Most crocodilians grab any food
that comes their way. But the
gavial is a specialist that preys
almost exclusively on fish. It lies
in ambush and snatches them
in its slender, elongated jaws.
After seizing its victim, the ga
vial surfaces to juggle the fish
around so it can be swallowed
headfirst. Sometimes it thrashes
the fish in the water to break it
up. Because it is cold-blooded,
left: The gavial spends most of the day basking in the sun to warm its massive body.
DID YOU KNOW? • Crocodiles swallow pebbles
to grind up food in their stom
achs. Gavials that have been
the gavial needs little food ener
gy. One bellyful lasts for a week.
A large gavial also takes water
birds and small mammals if it
can catch them, but it is virtual
ly harmless to humans. Gavials
from the sacred Ganges River
have been found with human
remains in their stomachs. But
it is almost certain that they fed
on corpses floating down the
river in Hindu funeral rites.
Right: The gavial tosses fish headfirst down its throat to avoid choking on the gills.
on catfish, which in turn prey
on tilapia fish caught by local
fishermen. The decline of the
found with anklets and brace- gavial has caused a popula-
lets in their stomachs proba- tion explosion among catfish,
bly swallowed them for the which have eaten most of the
same purpose, getting the tilapias. So the more catfish-
jewelry from human remains eating gavials there are, the
in the Ganges River. more tilapias there will be for
L • The gavial preys primarily __ I_ndian fishermen. _
~ GAVIAL &: MAN The gavial has been widely killed
for its skin. In addition, it has lost
much of its habitat as rivers have
been dammed to provide elec
tricity and irrigation to drought
prone rural India.
By 1975 fewer than 70 gavials
lived in the wild, and the Indian
government set up a breeding
program. Eggs were taken and
~ BREEDING In late winter or spring, the male
gavial tries to gather a harem of
three or four females. He attracts
them with whistles and hisses,
then mates with each female in
the water. When mating, the
pair sinks to the bottom with
bodies entwined.
Like all crocodilians, the female
gavial lays eggs. She digs a small,
shallow hole some 30 feet from
the river and deposits about 40
brittle-shelled eggs in the nest.
She chooses the site with care
to ensure the best possible con
ditions for incubation. The fe-
left: Each hatchling opens its shell with an egg tooth, then croaks to attract its mother.
young gavials reared to a length
of about four feet before being
released. At that size gavials can
usually look after themselves.
Today, the wild population is
about 2,000, but most of the
animals are too young to breed.
With fewer than 20 sexually ma
ture males now in circulation,
the species is still in danger.
male stays near the nest, often
lurking in the water nearby, and
chases off egg thieves such as
monitor lizards and jackals.
The warmer the weather, the
sooner the eggs hatch. After
two to three months, the hatch
lings emerge. Their mother digs
the nest open and guides the
tiny gavials to the safety of the
water. She often carries them in
her mouth, with their tiny legs
protruding between her teeth.
Despite this maternal care,
many of the young die. They
are snatched by predators or
swept away to drown in the
seasonal floods. Of the whole
clutch, only one may survive.
COMMON TOAD
"''--------.... CLASS ORDER '11IIIIIIII Amphibia Safientia
CARD 38~
GROUP 3: REPTILES & AMPHIBIANS FAMILY Bufonidae
GENUS & SPECIES Bufo bufo
Many people fear the common toad because of its appearance and poisonous skin. But this shy and docile amphibian is usually
harmless to humans, and it may even be a help to gardeners.
KEY FACTS
SIZES
Length: Male, 3 in. Female, 5 in.
Weight: Male, ~-2 oz. Female,
)4-40z.
BREEDING
Sexual maturity: Male, 4-5 years.
Female, 3-4 years.
Mating: February to April.
No. of eggs: 3,000-12,000 (2 or 3
larvae survive to adulthood).
Larva to adult: About 12 weeks.
LIFESTYLE
Habit: Mainly solitary.
Diet: Various invertebrates. Range of the common toad.
DISTRIBUTION Call: Male emits a rapid, high
pitched sound when alarmed and
a slower, longer croak during the
mating season.
Lifespan: 30-40 years.
Found in most of Europe, but not in Ireland, Corsica, Sardinia,
or the Balearic Islands. Also found in northwestern Africa and
temperate Asia as far east as Japan.
RELATED SPECIES CONSERVATION The 227 known species in the fam
ily Bufonidae include the American
toad, Bufo americanus, and Wood
house's toad, B. woodhousei.
Although the common toad is widespread, its habitat, like that
of all aquatic and semiaquatic species, is threatened by indus
trial pollution and the urbanization of rural areas.
FEATURES OF THE COMMON TOAD
Coloration: A mottled skin in shades of yellow and brown provides the toad with excellent camouflage in much of its natural habitat.
Poison: To deter predators, two kinds of venom are secreted from glands on the back and chest.
Eyes: A transparent protective "third eyelid," called the nictitating membrane, allows the toad to see underwater.
Tongue: Up to 4 inches long, pink, and
sticky. A hinge at the front of the mouth allows the toad to flick it in and out with amazing speed. It is activated by a reflex mechanism.
Limbs: Forelimbs are used to grasp prey and enable the
male to clasp the female when mating. Forefeet are
not webbed. The larger, more powerful hind
limbs propel the toad forward.
I
I
o r--fw ~ o it o r-o
~ ;; o co 0... (f) ::J
:;;
ill .-1 u::: fo Lf: w LL ::J o .-1
~ o ~ 0... 2 ;; co 0...
~ :; o X 2 o 2 @
In emergencies the common toad defends itself with a thick,
white poison. Secreted by glands surrounding the "warts" on
the toad's back, this poison works by paralysis. Although
enough venom can be produced to kill a dog, it is so sour
that it repels most dogs after a single sniff. Other predators
such as grass snakes, owls, or crows are not greatly affected
by the toad's venom, so they continue to attack the animal.
~ HABITS The common toad spends the summer alone but often hibernates with other toads. Although less active when hibernating, it does not actually sleep. It stops feeding and lives off fat stored in its body. It does not eat again until it mates in spring.
If alarmed, the toad can produce two kinds of poison from glands on both its back and chest. One poison is colorless and smells like mushrooms and vanilla . It has a numbing effect.
Right: If threatened, the common toad puffs up its body to display its venomous, warty skin.
The other thick, white venom is secreted only in emergencies.
The common toad is agile and has a good sense of direction. It climbs walls and trellises and can leap up to six inches.
~ FOOD Est HUNTING The adult common toad feeds on invertebrates such as spiders, ants, earthworms, slugs, caterpillars, beetles, and bees. It can handle poisonous prey, and it readily eats young frogs, newts, and lizards.
The toad hunts primarily at night. It can swim well and walk fast but is generally sedentary. It may move slowly, looking for signs of prey, but much of the time it sits and waits. When the toad sees prey, a reflex mecha-
Left: After it becomes an adult, the common toad leaves the pond but returns each year to breed.
I DID YOU KNOW? • The common toad can live underground for three years without food. It loses weight and survives on very little air. • The Greek philosopher Aristotle gave one of the first descriptions of the toad's pale pink tongue. • In medieval times, people thought the toad had the evil
nism activates its tongue. The sticky tongue flicks out, attaches itself to the prey, and returns in a split second. Because the toad lacks teeth, it crushes the prey against the roof of its mouth. It then swallows by retracting its eyeballs deep into its head to push the food down.
Toads compete for their food by shoving each other out of the way. They rarely attack one another but may eat the young of their own species.
Right: The common toad feeds heavily on earthworms and other invertebrates after breeding.
eye and could cast spells. It l was suspected of turning wine to vinegar and suckling milk from cows. Some believed there was a magical golden stone in the toad's head. • The English dish "toad-inthe-hole" was named for the toad's habit of hiding under the ground.
I 1- :,d NATUREWATCH The common toad breeds in water but lives most of its life in woods, fields, gardens, or sheds. Active mainly at night, it chooses a dark den in a tree stump, under stones, beneath thick plants, or in a hole in the ground.
~ BREEDING After hibernation, the adult male common toad heads for the nearest pond. Attracted by his nightly croaking, the female arrives up to two weeks later and is seized by the male. Using the swollen "nuptial pads" on his thumbs, he grips her around the stomach. Only one male can mate with a female. Others try to dislodge him, and the competition lasts for days.
The female lays two strings of jelly-covered eggs, which the
Left: Clasping the female, the male fertilizes the strings of jelly-covered eggs she releases into the water.
In October the toad hibernates in a deeper shelter. It may use its hind legs to dig a hole in sandy soil or to bury itself in a manure heap. In early February it heads for ponds to breed, then returns to its solitary life in summer.
male then fertilizes in the water. Spawning takes 10 to 28 hours. Parents do not tend the young .
Over the next 20 days, the offspring grows from an eyeless organism that cannot eat into a tadpole with a long tail, eyes, a mouth, and two rows of teeth. It eats plant matter and breathes through feathery gills. Four limbs gradually emerge, and the tadpole reabsorbs its tail, loses its teeth, and forms a membrane over its gills. It becomes a tiny toad, able to breathe internally, crouch, walk, and swim.
'" CARD 39.-J SKINK ,, ____________ G_ RO_ U_P_3: REPTILES & AMPHIBIANS ... CLASS ... ORDER ,. FAMILY
~ Reptilia ~ Squamata ~ Scincidae
Skinks are an extremely varied group of lizards. These reptiles have developed such a wide range of adaptations that it is hard to
believe they all belong to the same family.
KEY FACTS
SIZE
Body length: 1-24 in ., depending
on the species .
BREEDING
Method: Some skinks bear live
young; others lay eggs.
No. of young: Usually 1-25,
depending on the species. Maxi
mum on record, 67.
LIFESTYLE
Habit: Burrowing, tree-climbing,
or ground-dwelling. Mostly active
by day.
Diet: Small species eat inverte
brates; large species usually eat
plants.
RELATED SPECI ES
There are over 1,200 species of
skink worldwide, grouped in 85
genera. Their closest relatives are
spiny girdle-tailed lizards, family
Cordylidae, such as the sungazer,
Cordylus giganteus, of Africa.
DEFENSES OF SKINKS
Blue-tongued skink: Uses shock tactics for defense. When threatened, it opens its mouth and sticks out a startling bright blue tongue, often hissing menacingly at the same time.
©MCMXCIV IMP BV/IMP INC WILDLIFE FACT FILETM
Range of skinks.
DISTRIBUTION
Skinks are found in a wide variety of habitats in tropical and
temperate regions throughout the world. The majority of
species inhabit Southeast Asia and Australasia.
CONSERVATION
The majority of skinks are in no immediate danger, although
at least four species are classified as rare.
American five-lined skink: If attacked, it wriggles its bright blue tail conspicuously
while keeping the rest of its body still. If the predator seizes the tail, the
skink casts it off and retreats
Stump-tailed skink: Deters attackers with its bright blue tongue. Also has a fat tail that serves as a decoy. Predators are fooled into attacking this tough stump instead of the more vulnerable head.
PRINTED IN U.S.A. us P 6001 12 068 PACKET 68
Left: The giant Solomon Island skink can grow to two feet long. Its strong limbs and claws are perfect for life in the trees.
Skinks are the most numerous, widespread lizards in the
world. They live in all kinds of tropical and temperate
habita~from rainforests to deserts and grassy plains to
rocky mountains. Skinks have evolved a wide variety of
features to suit their environments. Some are blind, legless
burrowers, while others are powerful climbers and swimmers.
~ CHARACTERISTICS Skinks have a wide range of fea-tures. But most skinks are small and short-legged with smooth, shiny brown scales and long, slender tails.
Like most lizards, a skink usually walks by moving diagonally opposite legs and wriggling its body in a snakelike motion at each step. But some skinks have evolved differently to suit their habitats. Some species have no legs, while others have virtually useless remnants. For example,
the sandfish of Africa "swims" through the desert sand like an eel, retracting its almost useless legs into recesses in its flanks. In contrast, the green-blood skink is suited to climbing, with adhesive toe pads and strong legs.
The giant Solomon Island skink climbs with the aid of a muscular, prehensile (gripping) tail. The stump-tailed skink, on the other hand, has only a short tail, but it helps to protect the animal from predators.
~ BREEDING Skinks have a variety of breeding habits. Some species, such as the giant Solomon Island skink, give birth to one large, fully formed infant.
Other species lay clutches of up to 25 eggs. In certain species, such as the great plains skink of North America, the female incubates her eggs by
Left: Over a foot long, the stumptail, or shingleback, inhabits dry areas of Australia.
DID YOU KNOW? • The green-blood skink is unique among vertebrates in having green blood, green scales, a green tongue, and green eggs. • Most skinks have smooth scales, which make the animals very hard to catch. But
L-
curling her body around them. She also helps the young hatch by licking them clean as they emerge from their shells.
The females of other species abandon their eggs. Although they produce larger clutches than their more protective relatives, a large proportion of their eggs may be lost to predators.
Right: The female southeastern five-lined skink guards her eggs before and during hatching.
Left: Like the rainbow skink of southern Africa, most typical skinks feed mainly on insects and other small invertebrates.
Cunningham's skink has spiny scales with which it wedges itself into cracks. • Several burrowing skinks do not have legs or any sense of sight. They rely on vibrations and scent to detect their underground invertebrate prey.
~ FOOD & FEEDING Large skinks like the Solomon Island skink often eat plants. Small species like the sandfish eat insects, spiders, and millipedes.
Some species have more specialized diets. The marine skink preys on small crabs and sandhoppers on the rocky shores of
~ HABITS Most skinks are active by day. These secretive creatures spend much of their time hiding beneath logs, among fallen leaves, or even underground. But some species live in trees. The Solomon Island skink, for example, spends almost all its time in the branches, rarely descending to the ground.
Like all cold-blooded animals,
Left: The Cape legless skink can burrow under the sand to escape the intense midday heat.
Left: The sandfish possesses a streamlined head with a pointed snout for pushing through sand. Its mouth opens under the snout.
its habitat. Other shore-dwelling skinks eat scraps that seabirds drop during their breeding season. This food is so abundant that the skinks can live off their energy reserves for the rest of the year, after the birds with their scraps have disappeared.
a skink needs external warmth to raise its body temperature. As a result, it usually basks in the morning sun before foraging for food. By noon a skink may start to overheat, so it retreats into the shade to cool off, emerging later for another period of activity. When the temperature drops at the end of the day, a skink is forced to go back to its shelter. There it spends the night in a semidormant condition .
~RD40~ PARADOXICAL FROG
" .. CLASS '1IIIIIIII Amphibia
.. ORDER '1IIIIIIII Anura
GROUP 3: REPTILES & AMPHIBIANS FAMILY Pseudidae
.. GENUS & SPECIES '1IIIIIIII Pseudis paradoxa
The paradoxical frog looks normal enough, but the same cannot be said for its tadpoles. Three times the size of their parents,
these enormous babies actually shrink as they mature.
KEY FACTS ~~----------------------------------------------------~
SIZE
Length: Tadpole, up to lOin.
Adult, up to 3 in .
BREEDING
Mating: In tropical wet season.
Eggs: Laid in a mass of jelly in
the water.
LIFESTYLE Habit: Solitary outside the breed
ing season. Diet: Adult eats insects and small
crustaceans. Tadpole eats plant
matter such as algae.
51 RELATED SPECIES
~ There are 4 species of pseudid, or
shrinking, frogs including Pseudis bolbodactyla of Brazil. The para
doxical frog is the largest of the
family. All 4 species are related to
the true frogs, which include the
North American bullfrog, Rana catesbeiana; the green frog, R. clamatans; and the leopard frog,
R. pipiens, of North America.
Range of the paradoxical frog.
DISTRIBUTION
Found in scattered locations in eastem South America, from the
northern tip south through Amazonia to northern Argentina.
Also on the island of Trinidad, off the coast of Venezuela.
CONSERVATION
The paradoxical frog is in little immediate danger from humans
because it lives in very remote areas. Local populations are vul
nerable to habitat loss, however.
~ATURES OF THE PARADOXICAL FROG
Adult: Only a few inches long when fully grown.
Eyes: Large and bulging. Often the only part of the frog that is visible in the water.
Fingers: Extended like the toes. An opposable thumb enables the frog to grip prey tightly.
Young (shown to scale): At10 inches long, the tadpole is 3 times the size of its parents.
© MCMXCII IMP BV/ IMP INC WILDLIFE FACT FILpM PRINTED IN U.S.A.
Skin: Extremely slippery, enabling the frog to escape
the grasp of predators.
Feet: Large and webbed. Each toe has an extra joint
called a phalanx that allows the frog to extend its reach .
0160200621 PACKET 62
The paradoxical frog is seldom seen and rarely caught. It
lives in marshes and forest pools, where it hides under thick
vegetation. Only very determined zoologists have been able
to observe this elusive creature in the wild. For many years,
their observations were disputed because the facts about the
paradoxical frog were considered too strange to be true.
~ HABITS One of a number of unusual things about the paradoxical frog is its highly aquatic way of life. All frogs must stay moist in order to survive, but most species do not linger in the water. They return to land to search for prey in the damp grass or leaf debris.
By contrast, the paradoxical frog breeds, feeds, and sleeps in water, rarely leaving it. It is usually seen floating in a pool of water, with just its eyes and nostrils protruding above the surface. It prefers still waters
with thick, floating vegetation that offers plenty of cover. If the frog is alarmed, it dives beneath the foliage and disappears from view.
The paradoxical frog favors the more remote swamps and marshes of Trinidad and Amazonia, far from human habitation, and its elusive habits make it hard to find. As a result, little information exists about its behavior in the wild.
Right: The adult paradoxical frog grows very little and is dwarfed by its oversize offspring.
~ FOOD & FEEDING The adult paradoxical frog eats small water animals. Like most frogs, it has powerful hind legs with large webbed feet. Each of its long projecting toes has an extra joint called a phalanx.
These extra joints make its toes more dexterous and enable the frog to extend its reach. These toes facilitate combing through mud and flushing out insects and small crustaceans.
The frog's fingers are extended in the same way as its toes. The innermost finger acts as an opposable thumb, so that the frog
left: The paradoxical frog is more aquatic than most frogs and rarely leaves the water.
DID YOU KNOW? • A noisy creature, the para-doxical frog is more often heard than seen. It produces coughing grunts like those of a pig. • When the paradoxical frog and its tadpoles were first described, most scientists
can capture prey in its hands. The larva, or tadpole, of the
paradoxical frog feeds only on plant matter. Like most larvae, it eats as much as possible in order to build up the energy supplies necessary for its metamorphosis into an adult. The tadpole uses its horny teeth to scrape algae off rocks and water plants. It digests the tough plant cells in its elongated gut. The gut of the adult is proportionately much shorter, since its diet of animal matter is easier to digest.
Right: The adult paradoxical frog is only a few inches long, but it is the largest frog in its family.
assumed that they were different species. The true relationship between the adult frog and its young was finally proven by captive breeding. • In South America the huge tadpoles are caught and sold as delicacies in food markets.
~ BREEDING Most frogs lay their eggs in water in a mass of jelly. Small aquatic larvae, called tadpoles,
hatch from the eggs. As each tadpole develops, it exchanges its gills for lungs, grows legs, and loses its tail. By the time the tadpole changes into a tiny frog, its body has grown only slightly. It then grows into the much bigger adult frog.
The paradoxical frog develops in much the same way, with one major exception: the main growth stage occurs when it is still a tadpole. When it hatches,
left: The paradoxical frog is well adapted for escaping from predators. It is well camouflaged,and its slippery skin is very difficult to grasp.
the tadpole looks normal, but it grows at an amazing rate. A fully grown specimen may be 10 inches long-three times the size of its parents.
As it undergoes its metamorphosis into an adult, the tadpole sprouts legs, loses its tail, and develops the features typical of all frogs-a broad mouth, bulging eyes, and a short, angular body. The tadpole keeps shrinking day by day. By the time it becomes a recognizable frog, it is only one-third of its originallength.